EVENTS

The purpose of teaching

(I am taking a short vacation from new blog posts. I will begin posting new entries again, on August 27, 2007. Until then, I will repost some early ones. Today’s one is from March 24, 2005, edited and updated.)

I have been teaching for many years and encountered many wonderful students. I remember in particular two students who were in my modern physics courses that dealt with quantum mechanics, relativity, and cosmology.

Doug was an excellent student, demonstrating a wonderful understanding of all the topics we discussed in class. But across the top of his almost perfect final examination paper, I was amused to see that he had written, “I still don’t believe in relativity!”

The other student was Jamal and he is not as direct as Doug. He came into my office a few years after the course was over (and just before he was about to graduate) to say goodbye. We chatted awhile, I wished him well, and then as he was about to leave he turned to me and said hesitantly in his characteristically shy way: “Do you remember that stuff you taught us about how the universe originated in the Big Bang about 15 billion years ago? Well, I don’t really believe all that.” After a pause he went on, “It kind of conflicts with my religious beliefs.” He looked apprehensively at me, perhaps to see if I might be offended or angry or think less of him. But I simply smiled and let it pass. It did not bother me at all.

Why was I not upset that these two students had, after having two semester-long courses with me, still not accepted the fundamental ideas that I had been teaching? The answer is simple. The goal of my teaching is not to change what my students believe. It is to have them understand what practitioners in the field believe. And those are two very different teaching goals.

As I said, I have taught for many years. And it seems to me that teachers encounter three kinds of situations with students.

One is where students do not have much prior experience (either explicitly or implicitly) with the material being taught and don’t have strong feelings about it either way. This is usually the case with technical or highly specialized areas (such as learning the symptoms of some rare disease or applying the laws of quantum mechanics to the hydrogen atom). In such cases, students have little trouble accepting what is taught.

The second type of situation is where students’ life experiences have resulted in strongly held beliefs about a particular knowledge structure, even though the student may not always be consciously aware of having such beliefs. The physics education literature is full of examples that our life experiences conspire to create in people an Aristotelian understanding of mechanics. This makes it hard for them to accept Newtonian mechanics. Note that this difficulty exists even though the students have no particular attachment to Aristotle’s views on mechanics and may not have the faintest idea what they are. Overcoming this kind of implicit belief structure is not easy. Doug was an example of someone who had got over the first hurdle from Aristotelian to Newtonian mechanics, but was finding the next transition to Einsteinian relativistic ideas much harder to swallow.

The third kind of situation is where the student has strong and explicit beliefs about something. These kinds of beliefs, as in the case of Jamal, come from religion or politics or parents or other major influences in their lives. You cannot force such students to change their views and any instructor who tries to do so is foolish. If students think that you are trying to force them to a particular point of view, they are very good at telling you what they think you want to hear, while retaining their beliefs. In fact, trying to force or bully students to accept your point of view, apart from being highly unethical teaching practice, is a sure way of reinforcing the strength of their original views.

So Doug’s and Jamal’s rejection of my ideas did not bother me and I was actually pleased that they felt comfortable telling me so. They had every right to believe whatever they wanted to believe. But what I had a right to expect was that they had understood what I was trying to teach and could use those ideas to make arguments within those frameworks.

For example, if I had given an exam problem that required that the student demonstrate his understanding of relativistic physics to solve, and Doug had refused to answer the question because he did not believe in relativity or had answered it using his own private theories of physics, I would have had to mark him down.

Similarly, if I had asked Jamal to calculate the age of the universe using the cosmological theories we had discussed in class, and he had instead said that the universe was 6,000 years old because that is what the Bible said, then I would have to mark him down too. He is free to believe what he wants, but the point of the course is to learn how the physics community interprets the world, and be able to use that information.

Understanding this distinction is important because of the periodic appearance of demagogues who try to frighten people by asserting that colleges are indoctrinating students to think in a particular way. Such people seem to assume that students are like sheep who can be induced to believe almost anything the instructor wants them to and thus require legal protection. Anyone who has taught for any length of time and has listened closely to students will know that this is ridiculous. It is not that students are not influenced by teaching and do not change their minds but that the process is far more complex and subtle than it is usually portrayed, as I will discuss in the next posting.

My own advice to students is to listen carefully and courteously to what knowledgeable people have to say, learn what the community of scholars thinks about an issue, and be able to understand and use that information when necessary. Weigh the arguments for and against any issue but ultimately stand up for what you believe and even more importantly know why you believe it. Don’t ever feel forced to accept something just because some ‘expert’ or other authority figure (teacher, preacher, parent, political leader, pundit, or media talking head) tells you it is true. Believe things only when it makes sense to you and you are good and ready for it.